fix: Update embedding dimensions to 3072 and add Vercel Analytics

- Updated GOOGLE_EMBEDDING_DIMENSIONS to 3072 to match gemini-embedding-001 output
- Updated database schema embedding index from 768 to 3072 dimensions
- Recreated production database index with correct dimensions
- Added @vercel/analytics package for production analytics
- Added Analytics component to root layout

This fixes the galaxy visualization issue caused by dimension mismatch between
the embedding model output (3072) and the database index (768).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

db/schema.surql

@@ -68,9 +68,9 @@ DEFINE FIELD coords_3d ON TABLE node TYPE array<number>
 
 -- Define the vector search index.
 -- We use MTREE (or HNSW) for high-performance k-NN search.
--- The dimension (768) MUST match the output of the
--- 'text-embedding-004' model.
-DEFINE INDEX node_embedding_idx ON TABLE node FIELDS embedding MTREE DIMENSION 768;
+-- The dimension (3072) MUST match the output of the
+-- 'gemini-embedding-001' model.
+DEFINE INDEX node_embedding_idx ON TABLE node FIELDS embedding MTREE DIMENSION 3072;
 
 -- --------------------------------------------------
 -- Relation: links_to